Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed incurable primary malignant brain tumor
that has progressed during or is recurrent after prior initial therapy, including
radiotherapy

- Failed prior standard therapy

- Measurable disease by MRI or CT scan

- No brain stem tumors

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Karnofsky 60-100%

Life expectancy:

- At least 2 months

Hematopoietic:

- Hematological function normal

- WBC at least 2000/mm^3

- Platelet count at least 50,000/mm^3

Hepatic:

- No liver failure

- No evidence of hepatic insufficiency

- Bilirubin no greater than 2.5 mg/dL

- SGOT/SGPT no greater than 5 times upper limit of normal

Renal:

- No evidence of renal insufficiency

- Creatinine no greater than 2.5 mg/dL

- No history of renal conditions that contraindicate high dosages of sodium

Cardiovascular:

- No uncontrolled hypertension

- No history of congestive heart failure

- No chronic heart failure

- No other cardiovascular conditions that contraindicate high dosages of sodium

Pulmonary:

- No serious lung disease, such as severe chronic obstructive pulmonary disease

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception during and for 4 weeks after study
participation

- No medical or psychiatric illness that would preclude study treatment

- No active infection

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- At least 4 weeks since prior immunotherapy

- No concurrent immunomodulating agents

Chemotherapy:

- At least 4 weeks since prior chemotherapy, except in patients with disease
progression during initial therapy

- At least 6 weeks since prior nitrosoureas, except in patients with disease
progression during initial therapy

- No concurrent antineoplastic agents

Endocrine therapy:

- Corticosteroids allowed

Radiotherapy:

- See Disease Characteristics

- At least 8 weeks since prior radiotherapy, except in patients with disease
progression during initial therapy

Surgery:

- At least 4 weeks since prior surgery, except in patients with disease progression
during initial therapy

Other:

- Recovered from prior therapy

- Cytodifferentiating agents allowed